This invention relates to lawn and garden sprinklers, more particularly oscillating sprinklers.
Sprinklers have been used for many years to provide sufficient moisture upon a surface, such as a lawn comprised of grass, to ensure that plants growing on such surface have sufficient irrigation to support healthy growth and prevent disease or even dying. In recent years, oscillating sprinklers, such as U.S. Pat. Nos. 3,332,624, 4,721,248 and 4,568,023 have been developed to provide a more uniform spray pattern over a more or less rectangular area. Such oscillating sprinklers are usually driven by a "water motor" or the like, such as is disclosed in U.S. Pat. No. 4,417,691 or 5,052,621.
A continuing problem has been to provide a sprinkler, particularly an oscillating sprinkler, with a spray pattern that can cover different sized areas uniformly. Because an oscillating sprinkler typically delivers a spray pattern that is more or less rectangular, it is difficult to provide uniform moisture over an irregular shaped surface. In placing the oscillating sprinkler at differing locations necessary to cover an irregularly shaped lawn surface, it often occurs that the rectangular spray pattern will "overlap," causing some areas of the lawn surface to receive more irrigation than others.
The prior art discloses some efforts to provide a variable spray pattern. U.S. Pat. No. 3,423,024 teaches the use of a plurality of external restrictors in the form of a thumb wheel, each with a blocking valve element which may be maneuvered over the outside of a spray orifice, or water jet, to partially prevent water from exiting therefrom. U.S. Pat. No. 5,052,622 teaches the use of external individually operable check valves to block water flow to selected water jets. These devices are less than desirable in operation, the former because the valve elements are less than effective in blocking water flow from outside the spray nozzle of the water jets, and the latter because the check valves have to be individually manipulated, and are difficult to operate while the sprinkler is in use, often resulting in the operator getting wet while attempting to alter the spray pattern.
The present invention solves these problems by providing a novel cam-operated selector in cooperation with a plurality of water interruption plunger assemblies to open or close selected water jets. Thus, using the present invention the user can "dial in" a wide variety of spray patterns to cover a correspondingly wide variety of areas, all without risk of getting wet.